Remove quoted.matching.Sym

Since quoted patterns do not return open quotes, this abstraction does not have any purpose.
The only useful part of it is extracting the name of a binding, therefore instead of returning a Sym we return the name as a String directly.

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -708,7 +708,6 @@ class Definitions {
 
   @tu lazy val QuotedTypeModule: Symbol = QuotedTypeClass.companionModule
 
-  @tu lazy val QuotedMatchingSymClass: ClassSymbol = ctx.requiredClass("scala.quoted.matching.Sym")
   @tu lazy val TastyReflectionClass: ClassSymbol = ctx.requiredClass("scala.tasty.Reflection")
 
   @tu lazy val Unpickler_unpickleExpr: Symbol = ctx.requiredMethod("scala.internal.quoted.Unpickler.unpickleExpr")

compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala

@@ -242,11 +242,10 @@ trait QuotesAndSplices {
                     x => t.resType.subst(t, x).toFunctionType())
               case t => t
             }
-            val bindingExprTpe = AppliedType(defn.QuotedMatchingSymClass.typeRef, bindingType :: Nil)
             assert(ddef.name.startsWith("$"))
             val bindName = ddef.name.toString.stripPrefix("$").toTermName
-            val sym = ctx0.newPatternBoundSymbol(bindName, bindingExprTpe, ddef.span)
-            patBuf += Bind(sym, untpd.Ident(nme.WILDCARD).withType(bindingExprTpe)).withSpan(ddef.span)
+            val sym = ctx0.newPatternBoundSymbol(bindName, defn.StringType, ddef.span)
+            patBuf += Bind(sym, untpd.Ident(nme.WILDCARD).withType(defn.StringType)).withSpan(ddef.span)
           }
           super.transform(tree)
         case tdef: TypeDef if tdef.symbol.hasAnnotation(defn.InternalQuoted_patternBindHoleAnnot) =>

library/src/scala/internal/quoted/Matcher.scala

@@ -3,7 +3,6 @@ package scala.internal.quoted
 import scala.annotation.internal.sharable
 
 import scala.quoted._
-import scala.quoted.matching.Sym
 
 private[quoted] object Matcher {
 
@@ -134,7 +133,7 @@ private[quoted] object Matcher {
         }
 
         def bindingMatch(sym: Symbol) =
-          matched(new Sym(sym.name, sym))
+          matched(sym.name)
 
         (scrutinee, pattern) match {
 

library/src/scala/quoted/matching/Sym.scala

@@ -14,22 +14,22 @@ object Test {
     case '{ 1 + ($y: Int)} => y
     case '{ val a = 1 + ($y: Int); 3 } => y
     case '{ val $y: Int = $z; println(`$y`); 1 } =>
-      val a: quoted.matching.Sym[Int] = y
+      val a: String = y
       z
     case '{ (($y: Int) => 1 + `$y` + ($z: Int))(2) } =>
-      val a: quoted.matching.Sym[Int] = y
+      val a: String = y
       z
     case '{ def $ff: Int = $z; `$ff` } =>
-      val a: quoted.matching.Sym[Int] = ff
+      val a: String = ff
       z
     case '{ def $ff(i: Int): Int = $z; 2 } =>
-      val a: quoted.matching.Sym[Int => Int] = ff
+      val a: String = ff
       z
     case '{ def $ff(i: Int)(j: Int): Int = $z; 2 } =>
-      val a: quoted.matching.Sym[Int => Int => Int] = ff
+      val a: String = ff
       z
     case '{ def $ff[T](i: T): Int = $z; 2 } =>
-      val a: quoted.matching.Sym[[T] =>> T => Int] = ff
+      val a: String = ff
       z
     case '{ poly[$t]($x); 4 } => ???
     case '{ type $X; poly[`$X`]($x); 4 } => ???

tests/pos/quotedPatterns.scala

@@ -238,7 +238,7 @@ Result: Some(List(Expr(((x: scala.Int) => "abc"))))
 
 Scrutinee: ((x: scala.Int) => "abc")
 Pattern: ((x: scala.Int @scala.internal.quoted.CompileTime.patternBindHole) => scala.internal.quoted.CompileTime.patternHole[scala.Predef.String])
-Result: Some(List(Sym(x), Expr("abc")))
+Result: Some(List(String(x), Expr("abc")))
 
 Scrutinee: scala.StringContext.apply("abc", "xyz")
 Pattern: scala.StringContext.apply("abc", "xyz")
@@ -270,7 +270,7 @@ Pattern: {
   @scala.internal.quoted.CompileTime.patternBindHole val a: scala.Int = scala.internal.quoted.CompileTime.patternHole[scala.Int]
   ()
 }
-Result: Some(List(Sym(a), Expr(45)))
+Result: Some(List(String(a), Expr(45)))
 
 Scrutinee: {
   val a: scala.Int = 45
@@ -502,7 +502,7 @@ Pattern: {
   @scala.internal.quoted.CompileTime.patternBindHole def a: scala.Int = scala.internal.quoted.CompileTime.patternHole[scala.Int]
   ()
 }
-Result: Some(List(Sym(a), Expr(45)))
+Result: Some(List(String(a), Expr(45)))
 
 Scrutinee: {
   def a(x: scala.Int): scala.Int = 45
@@ -572,7 +572,7 @@ Pattern: {
   def a(x: scala.Int @scala.internal.quoted.CompileTime.patternBindHole): scala.Int = 45
   ()
 }
-Result: Some(List(Sym(x)))
+Result: Some(List(String(x)))
 
 Scrutinee: {
   def a(x: scala.Int): scala.Int = 45
@@ -582,7 +582,7 @@ Pattern: {
   def a(x: scala.Int @scala.internal.quoted.CompileTime.patternBindHole): scala.Int = 45
   ()
 }
-Result: Some(List(Sym(x)))
+Result: Some(List(String(x)))
 
 Scrutinee: {
   def a(x: scala.Int): scala.Int = x

tests/run-macros/quote-matcher-runtime.check

@@ -1,6 +1,4 @@
 import scala.quoted._
-import scala.quoted.matching._
-
 
 object Macros {
 
@@ -15,8 +13,8 @@ object Macros {
           s"Expr(${r.unseal.show})"
         case r: quoted.Type[_] =>
           s"Type(${r.unseal.show})"
-        case r: Sym[_] =>
-          s"Sym(${r.name})"
+        case r: String =>
+          s"String($r)"
       }
     }
 

tests/run-macros/quote-matcher-runtime/quoted_1.scala

@@ -1,6 +1,4 @@
 import scala.quoted._
-import scala.quoted.matching._
-
 
 object Macros {
 
@@ -13,8 +11,8 @@ object Macros {
       tup.toArray.toList.map {
         case r: quoted.Type[_] =>
           s"Type(${r.unseal.show})"
-        case r: Sym[_] =>
-          s"Sym(${r.name})"
+        case r: String =>
+          s"String($r)"
       }
     }